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<a href="ostream__log__msg__writer_8hpp.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a id="l00001" name="l00001"></a><span class="lineno">    1</span><span class="comment">/* Flow</span></div>
<div class="line"><a id="l00002" name="l00002"></a><span class="lineno">    2</span><span class="comment"> * Copyright 2023 Akamai Technologies, Inc.</span></div>
<div class="line"><a id="l00003" name="l00003"></a><span class="lineno">    3</span><span class="comment"> *</span></div>
<div class="line"><a id="l00004" name="l00004"></a><span class="lineno">    4</span><span class="comment"> * Licensed under the Apache License, Version 2.0 (the</span></div>
<div class="line"><a id="l00005" name="l00005"></a><span class="lineno">    5</span><span class="comment"> * &quot;License&quot;); you may not use this file except in</span></div>
<div class="line"><a id="l00006" name="l00006"></a><span class="lineno">    6</span><span class="comment"> * compliance with the License.  You may obtain a copy</span></div>
<div class="line"><a id="l00007" name="l00007"></a><span class="lineno">    7</span><span class="comment"> * of the License at</span></div>
<div class="line"><a id="l00008" name="l00008"></a><span class="lineno">    8</span><span class="comment"> *</span></div>
<div class="line"><a id="l00009" name="l00009"></a><span class="lineno">    9</span><span class="comment"> *   https://www.apache.org/licenses/LICENSE-2.0</span></div>
<div class="line"><a id="l00010" name="l00010"></a><span class="lineno">   10</span><span class="comment"> *</span></div>
<div class="line"><a id="l00011" name="l00011"></a><span class="lineno">   11</span><span class="comment"> * Unless required by applicable law or agreed to in</span></div>
<div class="line"><a id="l00012" name="l00012"></a><span class="lineno">   12</span><span class="comment"> * writing, software distributed under the License is</span></div>
<div class="line"><a id="l00013" name="l00013"></a><span class="lineno">   13</span><span class="comment"> * distributed on an &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR</span></div>
<div class="line"><a id="l00014" name="l00014"></a><span class="lineno">   14</span><span class="comment"> * CONDITIONS OF ANY KIND, either express or implied.</span></div>
<div class="line"><a id="l00015" name="l00015"></a><span class="lineno">   15</span><span class="comment"> * See the License for the specific language governing</span></div>
<div class="line"><a id="l00016" name="l00016"></a><span class="lineno">   16</span><span class="comment"> * permissions and limitations under the License. */</span></div>
<div class="line"><a id="l00017" name="l00017"></a><span class="lineno">   17</span><span class="comment"></span> </div>
<div class="line"><a id="l00018" name="l00018"></a><span class="lineno">   18</span><span class="comment">/// @file</span></div>
<div class="line"><a id="l00019" name="l00019"></a><span class="lineno">   19</span><span class="comment"></span><span class="preprocessor">#pragma once</span></div>
<div class="line"><a id="l00020" name="l00020"></a><span class="lineno">   20</span> </div>
<div class="line"><a id="l00021" name="l00021"></a><span class="lineno">   21</span><span class="preprocessor">#include &quot;<a class="code" href="log__fwd_8hpp.html">flow/log/log_fwd.hpp</a>&quot;</span></div>
<div class="line"><a id="l00022" name="l00022"></a><span class="lineno">   22</span><span class="comment">/* Subtlety: The following is technically not required -- log_fwd.hpp is enough to fwd-declare Config, and we</span></div>
<div class="line"><a id="l00023" name="l00023"></a><span class="lineno">   23</span><span class="comment"> * only mention Config* here.  However in practice we are likely indirectly included by a *_logger.hpp, and guys such</span></div>
<div class="line"><a id="l00024" name="l00024"></a><span class="lineno">   24</span><span class="comment"> * as (e.g.) Simple_ostream_logger all take Config* as ctor arg, and in practice the user almost always will want</span></div>
<div class="line"><a id="l00025" name="l00025"></a><span class="lineno">   25</span><span class="comment"> * to instantiate a Config and thus require the following header file.  Of course, we could just make them</span></div>
<div class="line"><a id="l00026" name="l00026"></a><span class="lineno">   26</span><span class="comment"> * #include it themselves, and generally that is fine/good/a goal of _fwd.hpp pattern.  (Even if the user is</span></div>
<div class="line"><a id="l00027" name="l00027"></a><span class="lineno">   27</span><span class="comment"> * directly using Ostream_log_msg_writer, the same reasoning applies: probably they need to instantiate a Config.)</span></div>
<div class="line"><a id="l00028" name="l00028"></a><span class="lineno">   28</span><span class="comment"> * So just for convenience for the vast majority of users, just give &#39;em this.  (Truthfully this is partially to</span></div>
<div class="line"><a id="l00029" name="l00029"></a><span class="lineno">   29</span><span class="comment"> * avoid breaking some user code written before the _fwd.hpp pattern was applied to Flow.  However in my (ygoldfel)</span></div>
<div class="line"><a id="l00030" name="l00030"></a><span class="lineno">   30</span><span class="comment"> * opinion it would still be a decent argument even without that. */</span></div>
<div class="line"><a id="l00031" name="l00031"></a><span class="lineno">   31</span><span class="preprocessor">#include &quot;<a class="code" href="config_8hpp.html">flow/log/config.hpp</a>&quot;</span></div>
<div class="line"><a id="l00032" name="l00032"></a><span class="lineno">   32</span><span class="preprocessor">#include &lt;array&gt;</span></div>
<div class="line"><a id="l00033" name="l00033"></a><span class="lineno">   33</span><span class="comment">// Normally we use boost.chrono in Flow; see explanation in class doc header below re. why std::chrono here.</span></div>
<div class="line"><a id="l00034" name="l00034"></a><span class="lineno">   34</span><span class="preprocessor">#include &lt;chrono&gt;</span></div>
<div class="line"><a id="l00035" name="l00035"></a><span class="lineno">   35</span><span class="preprocessor">#include &lt;ostream&gt;</span></div>
<div class="line"><a id="l00036" name="l00036"></a><span class="lineno">   36</span><span class="preprocessor">#include &lt;boost/io/ios_state.hpp&gt;</span></div>
<div class="line"><a id="l00037" name="l00037"></a><span class="lineno">   37</span><span class="preprocessor">#include &lt;vector&gt;</span></div>
<div class="line"><a id="l00038" name="l00038"></a><span class="lineno">   38</span> </div>
<div class="line"><a id="l00039" name="l00039"></a><span class="lineno">   39</span><span class="keyword">namespace </span><a class="code hl_namespace" href="namespaceflow_1_1log.html">flow::log</a></div>
<div class="line"><a id="l00040" name="l00040"></a><span class="lineno">   40</span>{</div>
<div class="line"><a id="l00041" name="l00041"></a><span class="lineno">   41</span> </div>
<div class="line"><a id="l00042" name="l00042"></a><span class="lineno">   42</span><span class="comment">// Types.</span></div>
<div class="line"><a id="l00043" name="l00043"></a><span class="lineno">   43</span><span class="comment"></span> </div>
<div class="line"><a id="l00044" name="l00044"></a><span class="lineno">   44</span><span class="comment">/**</span></div>
<div class="line"><a id="l00045" name="l00045"></a><span class="lineno">   45</span><span class="comment"> * Utility class, each object of which wraps a given `ostream` and outputs discrete messages to it adorned with time</span></div>
<div class="line"><a id="l00046" name="l00046"></a><span class="lineno">   46</span><span class="comment"> * stamps and other formatting such as separating newlines.  A Config object controls certain aspects of its behavior;</span></div>
<div class="line"><a id="l00047" name="l00047"></a><span class="lineno">   47</span><span class="comment"> * pass this to the constructor.  The Config may come from the user as passed to the Logger (if any) using `*this`;</span></div>
<div class="line"><a id="l00048" name="l00048"></a><span class="lineno">   48</span><span class="comment"> * or that Logger (if any) can make its own from scratch.</span></div>
<div class="line"><a id="l00049" name="l00049"></a><span class="lineno">   49</span><span class="comment"> *</span></div>
<div class="line"><a id="l00050" name="l00050"></a><span class="lineno">   50</span><span class="comment"> * It is assumed that between the first and last calls to log() no other code whatsoever writes to the underlying</span></div>
<div class="line"><a id="l00051" name="l00051"></a><span class="lineno">   51</span><span class="comment"> * stream (as passed to ctor) at any point -- including any formatters.  At `*this` destruction formatter state</span></div>
<div class="line"><a id="l00052" name="l00052"></a><span class="lineno">   52</span><span class="comment"> * is restored.</span></div>
<div class="line"><a id="l00053" name="l00053"></a><span class="lineno">   53</span><span class="comment"> *</span></div>
<div class="line"><a id="l00054" name="l00054"></a><span class="lineno">   54</span><span class="comment"> * ### Rationale ###</span></div>
<div class="line"><a id="l00055" name="l00055"></a><span class="lineno">   55</span><span class="comment"> * This optional (but recommended for most Logger implementations, though technically not limited to their use)</span></div>
<div class="line"><a id="l00056" name="l00056"></a><span class="lineno">   56</span><span class="comment"> * utility class typically sits between some &quot;physical&quot; output medium -- a buffer in memory, a file, etc. --</span></div>
<div class="line"><a id="l00057" name="l00057"></a><span class="lineno">   57</span><span class="comment"> * that can be written to using an `ostream` (e.g., `std::ostringstream`, util::String_ostream, `std::ofstream`);</span></div>
<div class="line"><a id="l00058" name="l00058"></a><span class="lineno">   58</span><span class="comment"> * and a Logger implementation that promises to output log messages to that output medium.  When Logger::do_log()</span></div>
<div class="line"><a id="l00059" name="l00059"></a><span class="lineno">   59</span><span class="comment"> * is called, the message string passed to it will contain the user&#39;s original message plus various Msg_metadata</span></div>
<div class="line"><a id="l00060" name="l00060"></a><span class="lineno">   60</span><span class="comment"> * nuggets (like time stamp, severity, source code location) either generated by FLOW_LOG_WITHOUT_CHECKING()</span></div>
<div class="line"><a id="l00061" name="l00061"></a><span class="lineno">   61</span><span class="comment"> * implementation or provided by user.  The idea is the Logger is to decide on the output format of the various</span></div>
<div class="line"><a id="l00062" name="l00062"></a><span class="lineno">   62</span><span class="comment"> * metadata plus the message.  Therefore, the present class outputs all those pieces (as appropriate) plus</span></div>
<div class="line"><a id="l00063" name="l00063"></a><span class="lineno">   63</span><span class="comment"> * separating newlines.  Any Logger is free to use any format it wants; and some `Logger`s might not even generate</span></div>
<div class="line"><a id="l00064" name="l00064"></a><span class="lineno">   64</span><span class="comment"> * any output character stream but rather forward everything elsewhere (maybe even over the network); but</span></div>
<div class="line"><a id="l00065" name="l00065"></a><span class="lineno">   65</span><span class="comment"> * Ostream_log_msg_writer provides a reasonable output format to a character stream, to be used or not as desired.</span></div>
<div class="line"><a id="l00066" name="l00066"></a><span class="lineno">   66</span><span class="comment"> *</span></div>
<div class="line"><a id="l00067" name="l00067"></a><span class="lineno">   67</span><span class="comment"> * ### Thread safety ###</span></div>
<div class="line"><a id="l00068" name="l00068"></a><span class="lineno">   68</span><span class="comment"> * For a given `*this`, the class is not safe for concurrent calls to log().  The using code must provide any such</span></div>
<div class="line"><a id="l00069" name="l00069"></a><span class="lineno">   69</span><span class="comment"> * guarantees.</span></div>
<div class="line"><a id="l00070" name="l00070"></a><span class="lineno">   70</span><span class="comment"> *</span></div>
<div class="line"><a id="l00071" name="l00071"></a><span class="lineno">   71</span><span class="comment"> * See thread safety notes and to-dos regarding config in Simple_ostream_logger doc header.  These apply here also.</span></div>
<div class="line"><a id="l00072" name="l00072"></a><span class="lineno">   72</span><span class="comment"> *</span></div>
<div class="line"><a id="l00073" name="l00073"></a><span class="lineno">   73</span><span class="comment"> * @internal</span></div>
<div class="line"><a id="l00074" name="l00074"></a><span class="lineno">   74</span><span class="comment"> * Impl notes</span></div>
<div class="line"><a id="l00075" name="l00075"></a><span class="lineno">   75</span><span class="comment"> * ----------</span></div>
<div class="line"><a id="l00076" name="l00076"></a><span class="lineno">   76</span><span class="comment"> * ### Human-readable time stamps, caching ###</span></div>
<div class="line"><a id="l00077" name="l00077"></a><span class="lineno">   77</span><span class="comment"> * At least optionally, log() adds a human-readable time stamp readout with the date, time (including seconds.usec</span></div>
<div class="line"><a id="l00078" name="l00078"></a><span class="lineno">   78</span><span class="comment"> * or better), and time zone.  Just getting that in a decent, predictable form, without localized weirdness, and</span></div>
<div class="line"><a id="l00079" name="l00079"></a><span class="lineno">   79</span><span class="comment"> * with sub-second precision can be non-trivial; `std::chrono` does not do it as of C++17; boost.chrono does but</span></div>
<div class="line"><a id="l00080" name="l00080"></a><span class="lineno">   80</span><span class="comment"> * only as of a certain quietly added features called time-point I/O v2 (as opposed to v1).  That in itself was</span></div>
<div class="line"><a id="l00081" name="l00081"></a><span class="lineno">   81</span><span class="comment"> * workable; however:</span></div>
<div class="line"><a id="l00082" name="l00082"></a><span class="lineno">   82</span><span class="comment"> *</span></div>
<div class="line"><a id="l00083" name="l00083"></a><span class="lineno">   83</span><span class="comment"> * When logging volume is very high, processor use by logging can be high, and as a percentage of cycles used,</span></div>
<div class="line"><a id="l00084" name="l00084"></a><span class="lineno">   84</span><span class="comment"> * we noticed that a high proportion was used in formatting the `time_point` into the `ostream` by boost.chrono.</span></div>
<div class="line"><a id="l00085" name="l00085"></a><span class="lineno">   85</span><span class="comment"> * Therefore we eventually moved to fmt, an output formatting library that is lightning-fast and whose API is</span></div>
<div class="line"><a id="l00086" name="l00086"></a><span class="lineno">   86</span><span class="comment"> * now folded into C++20 standard lib (as of this writing we are on C++17); not unlike boost.chrono long ago became</span></div>
<div class="line"><a id="l00087" name="l00087"></a><span class="lineno">   87</span><span class="comment"> * `std::chrono`.  fmt provides flexibly formattable `time_point` output as well, so we can get everything we want</span></div>
<div class="line"><a id="l00088" name="l00088"></a><span class="lineno">   88</span><span class="comment"> * just how we want it (in contrast with boost.chrono where it was merely a stroke of luck that the output</span></div>
<div class="line"><a id="l00089" name="l00089"></a><span class="lineno">   89</span><span class="comment"> * was acceptable).</span></div>
<div class="line"><a id="l00090" name="l00090"></a><span class="lineno">   90</span><span class="comment"> *</span></div>
<div class="line"><a id="l00091" name="l00091"></a><span class="lineno">   91</span><span class="comment"> * Moreover, we accomplish a slight additional speedup by *caching* the formatted output across log() calls;</span></div>
<div class="line"><a id="l00092" name="l00092"></a><span class="lineno">   92</span><span class="comment"> * in each log() printing it up to but excluding seconds; then adding the seconds plus sub-seconds in a separate,</span></div>
<div class="line"><a id="l00093" name="l00093"></a><span class="lineno">   93</span><span class="comment"> * less expensive fmt call.  The cached output needs to be updated once the previous cached value is no longer</span></div>
<div class="line"><a id="l00094" name="l00094"></a><span class="lineno">   94</span><span class="comment"> * applicable even up to the precision that is actually used.</span></div>
<div class="line"><a id="l00095" name="l00095"></a><span class="lineno">   95</span><span class="comment"> *</span></div>
<div class="line"><a id="l00096" name="l00096"></a><span class="lineno">   96</span><span class="comment"> * ### Why standard library time-points instead of boost.chrono? ###</span></div>
<div class="line"><a id="l00097" name="l00097"></a><span class="lineno">   97</span><span class="comment"> * In the rest of Flow we tend to prefer boost.chrono to `std::chrono`; they are extremely similar, but</span></div>
<div class="line"><a id="l00098" name="l00098"></a><span class="lineno">   98</span><span class="comment"> * boost.chrono adds a few features including some extra clocks which are useful.  However fmt accepts `std::chrono`</span></div>
<div class="line"><a id="l00099" name="l00099"></a><span class="lineno">   99</span><span class="comment"> * time points, so for this specific purpose we store an `std::chrono` time point in Msg_metadata.  At that point</span></div>
<div class="line"><a id="l00100" name="l00100"></a><span class="lineno">  100</span><span class="comment"> * it was also reasonable to just use `std::chrono` for other time-related needs in this small class.</span></div>
<div class="line"><a id="l00101" name="l00101"></a><span class="lineno">  101</span><span class="comment"> */</span></div>
<div class="line"><a id="l00102" name="l00102"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html">  102</a></span><span class="keyword">class </span><a class="code hl_class" href="classflow_1_1log_1_1Ostream__log__msg__writer.html">Ostream_log_msg_writer</a> :</div>
<div class="line"><a id="l00103" name="l00103"></a><span class="lineno">  103</span>  <span class="keyword">private</span> boost::noncopyable</div>
<div class="line"><a id="l00104" name="l00104"></a><span class="lineno">  104</span>{</div>
<div class="line"><a id="l00105" name="l00105"></a><span class="lineno">  105</span><span class="keyword">public</span>:</div>
<div class="line"><a id="l00106" name="l00106"></a><span class="lineno">  106</span>  <span class="comment">// Types.</span></div>
<div class="line"><a id="l00107" name="l00107"></a><span class="lineno">  107</span> </div>
<div class="line"><a id="l00108" name="l00108"></a><span class="lineno">  108</span>  <span class="comment">// Constructors/destructor.</span></div>
<div class="line"><a id="l00109" name="l00109"></a><span class="lineno">  109</span><span class="comment"></span> </div>
<div class="line"><a id="l00110" name="l00110"></a><span class="lineno">  110</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00111" name="l00111"></a><span class="lineno">  111</span><span class="comment">   * Constructs object wrapping the given `ostream`.  Does not write any characters to stream (so, for instance,</span></div>
<div class="line"><a id="l00112" name="l00112"></a><span class="lineno">  112</span><span class="comment">   * if it happens to be an `ofstream` then it is fine if it&#39;s not yet open or even associated with a path).  It may</span></div>
<div class="line"><a id="l00113" name="l00113"></a><span class="lineno">  113</span><span class="comment">   * however do stateful things such as format setting.</span></div>
<div class="line"><a id="l00114" name="l00114"></a><span class="lineno">  114</span><span class="comment">   *</span></div>
<div class="line"><a id="l00115" name="l00115"></a><span class="lineno">  115</span><span class="comment">   * If any non-default formatting has been applied to `os`, subsequent behavior is undefined.</span></div>
<div class="line"><a id="l00116" name="l00116"></a><span class="lineno">  116</span><span class="comment">   *</span></div>
<div class="line"><a id="l00117" name="l00117"></a><span class="lineno">  117</span><span class="comment">   * @param config</span></div>
<div class="line"><a id="l00118" name="l00118"></a><span class="lineno">  118</span><span class="comment">   *        Controls behavior of `*this`.  See thread safety notes in class doc header.</span></div>
<div class="line"><a id="l00119" name="l00119"></a><span class="lineno">  119</span><span class="comment">   *        This is saved *by reference* inside `*this`; it must remain valid through the last log() call.</span></div>
<div class="line"><a id="l00120" name="l00120"></a><span class="lineno">  120</span><span class="comment">   * @param os</span></div>
<div class="line"><a id="l00121" name="l00121"></a><span class="lineno">  121</span><span class="comment">   *        Stream to which to write subsequently via log().</span></div>
<div class="line"><a id="l00122" name="l00122"></a><span class="lineno">  122</span><span class="comment">   */</span></div>
<div class="line"><a id="l00123" name="l00123"></a><span class="lineno">  123</span>  <span class="keyword">explicit</span> <a class="code hl_function" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a701b932c4f46f1edb96a975ad7076ccf">Ostream_log_msg_writer</a>(<span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1log_1_1Config.html">Config</a>&amp; config, std::ostream&amp; os);</div>
<div class="line"><a id="l00124" name="l00124"></a><span class="lineno">  124</span><span class="comment"></span> </div>
<div class="line"><a id="l00125" name="l00125"></a><span class="lineno">  125</span><span class="comment">  /// Restores formatting state of `os` to how it was before entry to constructor.</span></div>
<div class="line"><a id="l00126" name="l00126"></a><span class="lineno">  126</span><span class="comment"></span>  <a class="code hl_function" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aa05b822916ceb37db219ec73563b146d">~Ostream_log_msg_writer</a>() <span class="keyword">noexcept</span>;</div>
<div class="line"><a id="l00127" name="l00127"></a><span class="lineno">  127</span> </div>
<div class="line"><a id="l00128" name="l00128"></a><span class="lineno">  128</span>  <span class="comment">// Methods.</span></div>
<div class="line"><a id="l00129" name="l00129"></a><span class="lineno">  129</span><span class="comment"></span> </div>
<div class="line"><a id="l00130" name="l00130"></a><span class="lineno">  130</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00131" name="l00131"></a><span class="lineno">  131</span><span class="comment">   * Logs to the wrapped `ostream` the given message and associated metadata like severity and time stamp; plus</span></div>
<div class="line"><a id="l00132" name="l00132"></a><span class="lineno">  132</span><span class="comment">   * a newline.</span></div>
<div class="line"><a id="l00133" name="l00133"></a><span class="lineno">  133</span><span class="comment">   *</span></div>
<div class="line"><a id="l00134" name="l00134"></a><span class="lineno">  134</span><span class="comment">   * @param metadata</span></div>
<div class="line"><a id="l00135" name="l00135"></a><span class="lineno">  135</span><span class="comment">   *        See `*metadata` in Logger::do_log().</span></div>
<div class="line"><a id="l00136" name="l00136"></a><span class="lineno">  136</span><span class="comment">   * @param msg</span></div>
<div class="line"><a id="l00137" name="l00137"></a><span class="lineno">  137</span><span class="comment">   *        The message.  No terminating newline is assumed (though there is no rule against it; but</span></div>
<div class="line"><a id="l00138" name="l00138"></a><span class="lineno">  138</span><span class="comment">   *        if one is present, a blank line will appear in wrapped `ostream`).</span></div>
<div class="line"><a id="l00139" name="l00139"></a><span class="lineno">  139</span><span class="comment">   */</span></div>
<div class="line"><a id="l00140" name="l00140"></a><span class="lineno">  140</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aba0a94e36e435aeb67bbc25fee8380f7">log</a>(<span class="keyword">const</span> <a class="code hl_struct" href="structflow_1_1log_1_1Msg__metadata.html">Msg_metadata</a>&amp; metadata, <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a> msg);</div>
<div class="line"><a id="l00141" name="l00141"></a><span class="lineno">  141</span> </div>
<div class="line"><a id="l00142" name="l00142"></a><span class="lineno">  142</span><span class="keyword">private</span>:</div>
<div class="line"><a id="l00143" name="l00143"></a><span class="lineno">  143</span> </div>
<div class="line"><a id="l00144" name="l00144"></a><span class="lineno">  144</span>  <span class="comment">// Types.</span></div>
<div class="line"><a id="l00145" name="l00145"></a><span class="lineno">  145</span><span class="comment"></span> </div>
<div class="line"><a id="l00146" name="l00146"></a><span class="lineno">  146</span><span class="comment">  /// Short-hand for an `ostream` state saver.</span></div>
<div class="line"><a id="l00147" name="l00147"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a418dcc115e27764db1a81077792d8e43">  147</a></span><span class="comment"></span>  <span class="keyword">using </span><a class="code hl_typedef" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a418dcc115e27764db1a81077792d8e43">Ostream_state</a> = boost::io::ios_all_saver;</div>
<div class="line"><a id="l00148" name="l00148"></a><span class="lineno">  148</span> </div>
<div class="line"><a id="l00149" name="l00149"></a><span class="lineno">  149</span>  <span class="comment">// Methods.</span></div>
<div class="line"><a id="l00150" name="l00150"></a><span class="lineno">  150</span><span class="comment"></span> </div>
<div class="line"><a id="l00151" name="l00151"></a><span class="lineno">  151</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00152" name="l00152"></a><span class="lineno">  152</span><span class="comment">   * log() implementation with time stamp = seconds.microseconds since Epoch.</span></div>
<div class="line"><a id="l00153" name="l00153"></a><span class="lineno">  153</span><span class="comment">   *</span></div>
<div class="line"><a id="l00154" name="l00154"></a><span class="lineno">  154</span><span class="comment">   * @param metadata</span></div>
<div class="line"><a id="l00155" name="l00155"></a><span class="lineno">  155</span><span class="comment">   *        See log().</span></div>
<div class="line"><a id="l00156" name="l00156"></a><span class="lineno">  156</span><span class="comment">   * @param msg</span></div>
<div class="line"><a id="l00157" name="l00157"></a><span class="lineno">  157</span><span class="comment">   *        See log().</span></div>
<div class="line"><a id="l00158" name="l00158"></a><span class="lineno">  158</span><span class="comment">   */</span></div>
<div class="line"><a id="l00159" name="l00159"></a><span class="lineno">  159</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#ab0f5d7c5f289defcded5fa3560059411">do_log_with_epoch_time_stamp</a>(<span class="keyword">const</span> <a class="code hl_struct" href="structflow_1_1log_1_1Msg__metadata.html">Msg_metadata</a>&amp; metadata, <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a> msg);</div>
<div class="line"><a id="l00160" name="l00160"></a><span class="lineno">  160</span><span class="comment"></span> </div>
<div class="line"><a id="l00161" name="l00161"></a><span class="lineno">  161</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00162" name="l00162"></a><span class="lineno">  162</span><span class="comment">   * log() implementation with time stamp = date/time with microsecond+ resolution/time zone, in</span></div>
<div class="line"><a id="l00163" name="l00163"></a><span class="lineno">  163</span><span class="comment">   * current OS time zone.</span></div>
<div class="line"><a id="l00164" name="l00164"></a><span class="lineno">  164</span><span class="comment">   *</span></div>
<div class="line"><a id="l00165" name="l00165"></a><span class="lineno">  165</span><span class="comment">   * @param metadata</span></div>
<div class="line"><a id="l00166" name="l00166"></a><span class="lineno">  166</span><span class="comment">   *        See log().</span></div>
<div class="line"><a id="l00167" name="l00167"></a><span class="lineno">  167</span><span class="comment">   * @param msg</span></div>
<div class="line"><a id="l00168" name="l00168"></a><span class="lineno">  168</span><span class="comment">   *        See log().</span></div>
<div class="line"><a id="l00169" name="l00169"></a><span class="lineno">  169</span><span class="comment">   */</span></div>
<div class="line"><a id="l00170" name="l00170"></a><span class="lineno">  170</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a53d47232844dc7060ee95b4d831bbe29">do_log_with_human_friendly_time_stamp</a>(<span class="keyword">const</span> <a class="code hl_struct" href="structflow_1_1log_1_1Msg__metadata.html">Msg_metadata</a>&amp; metadata, <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a> msg);</div>
<div class="line"><a id="l00171" name="l00171"></a><span class="lineno">  171</span><span class="comment"></span> </div>
<div class="line"><a id="l00172" name="l00172"></a><span class="lineno">  172</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00173" name="l00173"></a><span class="lineno">  173</span><span class="comment">   * Remainder of log() functionality after either do_log_with_epoch_time_stamp() or</span></div>
<div class="line"><a id="l00174" name="l00174"></a><span class="lineno">  174</span><span class="comment">   * do_log_with_human_friendly_time_stamp(), once either has logged the time stamp.</span></div>
<div class="line"><a id="l00175" name="l00175"></a><span class="lineno">  175</span><span class="comment">   *</span></div>
<div class="line"><a id="l00176" name="l00176"></a><span class="lineno">  176</span><span class="comment">   * @param metadata</span></div>
<div class="line"><a id="l00177" name="l00177"></a><span class="lineno">  177</span><span class="comment">   *        See log().</span></div>
<div class="line"><a id="l00178" name="l00178"></a><span class="lineno">  178</span><span class="comment">   * @param msg</span></div>
<div class="line"><a id="l00179" name="l00179"></a><span class="lineno">  179</span><span class="comment">   *        See log().</span></div>
<div class="line"><a id="l00180" name="l00180"></a><span class="lineno">  180</span><span class="comment">   */</span></div>
<div class="line"><a id="l00181" name="l00181"></a><span class="lineno">  181</span>  <span class="keywordtype">void</span> <a class="code hl_function" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a7ac568ffa478c6fc64775c23b00d3fb3">log_past_time_stamp</a>(<span class="keyword">const</span> <a class="code hl_struct" href="structflow_1_1log_1_1Msg__metadata.html">Msg_metadata</a>&amp; metadata, <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a> msg);</div>
<div class="line"><a id="l00182" name="l00182"></a><span class="lineno">  182</span> </div>
<div class="line"><a id="l00183" name="l00183"></a><span class="lineno">  183</span>  <span class="comment">// Constants.</span></div>
<div class="line"><a id="l00184" name="l00184"></a><span class="lineno">  184</span><span class="comment"></span> </div>
<div class="line"><a id="l00185" name="l00185"></a><span class="lineno">  185</span><span class="comment">  /// Mapping from Sev to its brief string description.</span></div>
<div class="line"><a id="l00186" name="l00186"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a0b99bff54e9784c072061ba35914d7ce">  186</a></span><span class="comment"></span>  <span class="keyword">static</span> <span class="keyword">const</span> std::vector&lt;util::String_view&gt; <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a0b99bff54e9784c072061ba35914d7ce">S_SEV_STRS</a>;</div>
<div class="line"><a id="l00187" name="l00187"></a><span class="lineno">  187</span><span class="comment"></span> </div>
<div class="line"><a id="l00188" name="l00188"></a><span class="lineno">  188</span><span class="comment">  /// Jan 1, 1970, 00:00.</span></div>
<div class="line"><a id="l00189" name="l00189"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a192af9b871a5243ccd8ece7ba10f46a4">  189</a></span><span class="comment"></span>  <span class="keyword">static</span> <span class="keyword">const</span> boost::chrono::system_clock::time_point <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a192af9b871a5243ccd8ece7ba10f46a4">S_POSIX_EPOCH</a>;</div>
<div class="line"><a id="l00190" name="l00190"></a><span class="lineno">  190</span><span class="comment"></span> </div>
<div class="line"><a id="l00191" name="l00191"></a><span class="lineno">  191</span><span class="comment">  /// Example human-readable time stamp output, up to but excluding seconds, for compile-time size calculations.</span></div>
<div class="line"><a id="l00192" name="l00192"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a63185c1743f22be5de7e453424bca50e">  192</a></span><span class="comment"></span>  <span class="keyword">static</span> <span class="keyword">constexpr</span> <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a> <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a63185c1743f22be5de7e453424bca50e">S_HUMAN_FRIENDLY_TIME_STAMP_MIN_SZ_TEMPLATE</a>{<span class="stringliteral">&quot;2024-02-05 22:09:&quot;</span>};</div>
<div class="line"><a id="l00193" name="l00193"></a><span class="lineno">  193</span><span class="comment"></span> </div>
<div class="line"><a id="l00194" name="l00194"></a><span class="lineno">  194</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00195" name="l00195"></a><span class="lineno">  195</span><span class="comment">   * Example human-readable time stamp output, starting with seconds, for compile-time size calculations.</span></div>
<div class="line"><a id="l00196" name="l00196"></a><span class="lineno">  196</span><span class="comment">   *</span></div>
<div class="line"><a id="l00197" name="l00197"></a><span class="lineno">  197</span><span class="comment">   * ### Subtlety ###</span></div>
<div class="line"><a id="l00198" name="l00198"></a><span class="lineno">  198</span><span class="comment">   * fmt docs say `%S` will use the precision &quot;available&quot;; in practice in our tested Linuxes it is</span></div>
<div class="line"><a id="l00199" name="l00199"></a><span class="lineno">  199</span><span class="comment">   * nanoseconds; in the past I (ygoldfel) have also seen microseconds printed in this situation; might be</span></div>
<div class="line"><a id="l00200" name="l00200"></a><span class="lineno">  200</span><span class="comment">   * some artifact of an internal time-formatting system API; whatever.  However, it is unlikely it will in</span></div>
<div class="line"><a id="l00201" name="l00201"></a><span class="lineno">  201</span><span class="comment">   * practice be better than nanoseconds; hence for our size-reserving purposes the template string with</span></div>
<div class="line"><a id="l00202" name="l00202"></a><span class="lineno">  202</span><span class="comment">   * nanoseconds should suffice.</span></div>
<div class="line"><a id="l00203" name="l00203"></a><span class="lineno">  203</span><span class="comment">   *</span></div>
<div class="line"><a id="l00204" name="l00204"></a><span class="lineno">  204</span><span class="comment">   * (It also says that if there is no sub-second value, then it won&#39;t print the sub-second portion; but this</span></div>
<div class="line"><a id="l00205" name="l00205"></a><span class="lineno">  205</span><span class="comment">   * appears to be poorly worded documentation: It prints `.000000000` just fine.)</span></div>
<div class="line"><a id="l00206" name="l00206"></a><span class="lineno">  206</span><span class="comment">   */</span></div>
<div class="line"><a id="l00207" name="l00207"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a5975ce26de8209e2632f90f635cc5291">  207</a></span>  <span class="keyword">static</span> <span class="keyword">constexpr</span> <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a> <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a5975ce26de8209e2632f90f635cc5291">S_HUMAN_FRIENDLY_TIME_STAMP_REST_SZ_TEMPLATE</a>{<span class="stringliteral">&quot;31.357246045 +0000 &quot;</span>};</div>
<div class="line"><a id="l00208" name="l00208"></a><span class="lineno">  208</span> </div>
<div class="line"><a id="l00209" name="l00209"></a><span class="lineno">  209</span>  <span class="comment">// Data.</span></div>
<div class="line"><a id="l00210" name="l00210"></a><span class="lineno">  210</span><span class="comment"></span> </div>
<div class="line"><a id="l00211" name="l00211"></a><span class="lineno">  211</span><span class="comment">  /// Reference to the config object passed to constructor.  See notes on thread safety.</span></div>
<div class="line"><a id="l00212" name="l00212"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a9a95b0f429db5e9b19055cf251b063a7">  212</a></span><span class="comment"></span>  <span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1log_1_1Config.html">Config</a>&amp; <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a9a95b0f429db5e9b19055cf251b063a7">m_config</a>;</div>
<div class="line"><a id="l00213" name="l00213"></a><span class="lineno">  213</span><span class="comment"></span> </div>
<div class="line"><a id="l00214" name="l00214"></a><span class="lineno">  214</span><span class="comment">  /// Pointer to function that log() will forward to when invoked.</span></div>
<div class="line"><a id="l00215" name="l00215"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a078336512565196f18debc72acc2e73f">  215</a></span><span class="comment"></span>  <span class="keyword">const</span> <a class="code hl_class" href="classflow_1_1Function.html">Function</a>&lt;void (<a class="code hl_class" href="classflow_1_1log_1_1Ostream__log__msg__writer.html">Ostream_log_msg_writer</a>*, <span class="keyword">const</span> <a class="code hl_struct" href="structflow_1_1log_1_1Msg__metadata.html">Msg_metadata</a>&amp;, <a class="code hl_typedef" href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">util::String_view</a>)&gt; <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a078336512565196f18debc72acc2e73f">m_do_log_func</a>;</div>
<div class="line"><a id="l00216" name="l00216"></a><span class="lineno">  216</span><span class="comment"></span> </div>
<div class="line"><a id="l00217" name="l00217"></a><span class="lineno">  217</span><span class="comment">  /// Reference to stream to which to log messages.</span></div>
<div class="line"><a id="l00218" name="l00218"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#ac37b6d6bbfb5c9feefd35fd78cc66dad">  218</a></span><span class="comment"></span>  std::ostream&amp; <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#ac37b6d6bbfb5c9feefd35fd78cc66dad">m_os</a>;</div>
<div class="line"><a id="l00219" name="l00219"></a><span class="lineno">  219</span><span class="comment"></span> </div>
<div class="line"><a id="l00220" name="l00220"></a><span class="lineno">  220</span><span class="comment">  /// Formatter state of #m_os at construction.  Used at least in destructor (as of this writing) to restore it.</span></div>
<div class="line"><a id="l00221" name="l00221"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aaf6caa588e382495f7605da38caa42bf">  221</a></span><span class="comment"></span>  <a class="code hl_typedef" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a418dcc115e27764db1a81077792d8e43">Ostream_state</a> <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aaf6caa588e382495f7605da38caa42bf">m_clean_os_state</a>;</div>
<div class="line"><a id="l00222" name="l00222"></a><span class="lineno">  222</span><span class="comment"></span> </div>
<div class="line"><a id="l00223" name="l00223"></a><span class="lineno">  223</span><span class="comment">  /// Buffer storing the last log() time stamp in human-friendly form, including a NUL at the end.</span></div>
<div class="line"><a id="l00224" name="l00224"></a><span class="lineno">  224</span><span class="comment"></span>  std::array&lt;char, <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a63185c1743f22be5de7e453424bca50e">S_HUMAN_FRIENDLY_TIME_STAMP_MIN_SZ_TEMPLATE</a>.size()</div>
<div class="line"><a id="l00225" name="l00225"></a><span class="lineno">  225</span>                   + <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a5975ce26de8209e2632f90f635cc5291">S_HUMAN_FRIENDLY_TIME_STAMP_REST_SZ_TEMPLATE</a>.size() + 1&gt;</div>
<div class="line"><a id="l00226" name="l00226"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a1c32abeff2a91c303a0568df84e9d3fe">  226</a></span>    <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a1c32abeff2a91c303a0568df84e9d3fe">m_last_human_friendly_time_stamp_str</a>;</div>
<div class="line"><a id="l00227" name="l00227"></a><span class="lineno">  227</span><span class="comment"></span> </div>
<div class="line"><a id="l00228" name="l00228"></a><span class="lineno">  228</span><span class="comment">  /// Length of string in #m_last_human_friendly_time_stamp_str (excluding any NUL).</span></div>
<div class="line"><a id="l00229" name="l00229"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a128cbd9b57957c6d53ca064228930391">  229</a></span><span class="comment"></span>  <span class="keywordtype">size_t</span> <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a128cbd9b57957c6d53ca064228930391">m_last_human_friendly_time_stamp_str_sz</a>;</div>
<div class="line"><a id="l00230" name="l00230"></a><span class="lineno">  230</span><span class="comment"></span> </div>
<div class="line"><a id="l00231" name="l00231"></a><span class="lineno">  231</span><span class="comment">  /**</span></div>
<div class="line"><a id="l00232" name="l00232"></a><span class="lineno">  232</span><span class="comment">   * As used in the caching-for-perf algorithm in do_log_with_human_friendly_time_stamp(),</span></div>
<div class="line"><a id="l00233" name="l00233"></a><span class="lineno">  233</span><span class="comment">   * this is the seconds-precision version of high-precision Msg_metadata::m_called_when, when</span></div>
<div class="line"><a id="l00234" name="l00234"></a><span class="lineno">  234</span><span class="comment">   * do_log_with_human_friendly_time_stamp() last had to perform full formatted-output into</span></div>
<div class="line"><a id="l00235" name="l00235"></a><span class="lineno">  235</span><span class="comment">   * #m_last_human_friendly_time_stamp_str.</span></div>
<div class="line"><a id="l00236" name="l00236"></a><span class="lineno">  236</span><span class="comment">   */</span></div>
<div class="line"><a id="l00237" name="l00237"></a><span class="lineno"><a class="line" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a716e6a13b113019834de45b28c577a0a">  237</a></span>  std::chrono::time_point&lt;std::chrono::system_clock, std::chrono::seconds&gt; <a class="code hl_variable" href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a716e6a13b113019834de45b28c577a0a">m_cached_rounded_time_stamp</a>;</div>
<div class="line"><a id="l00238" name="l00238"></a><span class="lineno">  238</span>}; <span class="comment">// class Ostream_log_msg_writer</span></div>
<div class="line"><a id="l00239" name="l00239"></a><span class="lineno">  239</span> </div>
<div class="line"><a id="l00240" name="l00240"></a><span class="lineno">  240</span>} <span class="comment">// namespace flow::log</span></div>
<div class="ttc" id="aclassflow_1_1Function_html"><div class="ttname"><a href="classflow_1_1Function.html">flow::Function</a></div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00512">common.hpp:512</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Config_html"><div class="ttname"><a href="classflow_1_1log_1_1Config.html">flow::log::Config</a></div><div class="ttdoc">Class used to configure the filtering and logging behavior of Loggers; its use in your custom Loggers...</div><div class="ttdef"><b>Definition:</b> <a href="config_8hpp_source.html#l00316">config.hpp:317</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html">flow::log::Ostream_log_msg_writer</a></div><div class="ttdoc">Utility class, each object of which wraps a given ostream and outputs discrete messages to it adorned...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00102">ostream_log_msg_writer.hpp:104</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a078336512565196f18debc72acc2e73f"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a078336512565196f18debc72acc2e73f">flow::log::Ostream_log_msg_writer::m_do_log_func</a></div><div class="ttdeci">const Function&lt; void(Ostream_log_msg_writer *, const Msg_metadata &amp;, util::String_view)&gt; m_do_log_func</div><div class="ttdoc">Pointer to function that log() will forward to when invoked.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00215">ostream_log_msg_writer.hpp:215</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a0b99bff54e9784c072061ba35914d7ce"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a0b99bff54e9784c072061ba35914d7ce">flow::log::Ostream_log_msg_writer::S_SEV_STRS</a></div><div class="ttdeci">static const std::vector&lt; util::String_view &gt; S_SEV_STRS</div><div class="ttdoc">Mapping from Sev to its brief string description.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00186">ostream_log_msg_writer.hpp:186</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a128cbd9b57957c6d53ca064228930391"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a128cbd9b57957c6d53ca064228930391">flow::log::Ostream_log_msg_writer::m_last_human_friendly_time_stamp_str_sz</a></div><div class="ttdeci">size_t m_last_human_friendly_time_stamp_str_sz</div><div class="ttdoc">Length of string in m_last_human_friendly_time_stamp_str (excluding any NUL).</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00229">ostream_log_msg_writer.hpp:229</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a192af9b871a5243ccd8ece7ba10f46a4"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a192af9b871a5243ccd8ece7ba10f46a4">flow::log::Ostream_log_msg_writer::S_POSIX_EPOCH</a></div><div class="ttdeci">static const boost::chrono::system_clock::time_point S_POSIX_EPOCH</div><div class="ttdoc">Jan 1, 1970, 00:00.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00189">ostream_log_msg_writer.hpp:189</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a1c32abeff2a91c303a0568df84e9d3fe"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a1c32abeff2a91c303a0568df84e9d3fe">flow::log::Ostream_log_msg_writer::m_last_human_friendly_time_stamp_str</a></div><div class="ttdeci">std::array&lt; char, S_HUMAN_FRIENDLY_TIME_STAMP_MIN_SZ_TEMPLATE.size()+S_HUMAN_FRIENDLY_TIME_STAMP_REST_SZ_TEMPLATE.size()+1 &gt; m_last_human_friendly_time_stamp_str</div><div class="ttdoc">Buffer storing the last log() time stamp in human-friendly form, including a NUL at the end.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00226">ostream_log_msg_writer.hpp:226</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a418dcc115e27764db1a81077792d8e43"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a418dcc115e27764db1a81077792d8e43">flow::log::Ostream_log_msg_writer::Ostream_state</a></div><div class="ttdeci">boost::io::ios_all_saver Ostream_state</div><div class="ttdoc">Short-hand for an ostream state saver.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00147">ostream_log_msg_writer.hpp:147</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a53d47232844dc7060ee95b4d831bbe29"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a53d47232844dc7060ee95b4d831bbe29">flow::log::Ostream_log_msg_writer::do_log_with_human_friendly_time_stamp</a></div><div class="ttdeci">void do_log_with_human_friendly_time_stamp(const Msg_metadata &amp;metadata, util::String_view msg)</div><div class="ttdoc">log() implementation with time stamp = date/time with microsecond+ resolution/time zone,...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8cpp_source.html#l00105">ostream_log_msg_writer.cpp:105</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a5975ce26de8209e2632f90f635cc5291"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a5975ce26de8209e2632f90f635cc5291">flow::log::Ostream_log_msg_writer::S_HUMAN_FRIENDLY_TIME_STAMP_REST_SZ_TEMPLATE</a></div><div class="ttdeci">static constexpr util::String_view S_HUMAN_FRIENDLY_TIME_STAMP_REST_SZ_TEMPLATE</div><div class="ttdoc">Example human-readable time stamp output, starting with seconds, for compile-time size calculations.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00207">ostream_log_msg_writer.hpp:207</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a63185c1743f22be5de7e453424bca50e"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a63185c1743f22be5de7e453424bca50e">flow::log::Ostream_log_msg_writer::S_HUMAN_FRIENDLY_TIME_STAMP_MIN_SZ_TEMPLATE</a></div><div class="ttdeci">static constexpr util::String_view S_HUMAN_FRIENDLY_TIME_STAMP_MIN_SZ_TEMPLATE</div><div class="ttdoc">Example human-readable time stamp output, up to but excluding seconds, for compile-time size calculat...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00192">ostream_log_msg_writer.hpp:192</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a701b932c4f46f1edb96a975ad7076ccf"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a701b932c4f46f1edb96a975ad7076ccf">flow::log::Ostream_log_msg_writer::Ostream_log_msg_writer</a></div><div class="ttdeci">Ostream_log_msg_writer(const Config &amp;config, std::ostream &amp;os)</div><div class="ttdoc">Constructs object wrapping the given ostream.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8cpp_source.html#l00038">ostream_log_msg_writer.cpp:38</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a716e6a13b113019834de45b28c577a0a"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a716e6a13b113019834de45b28c577a0a">flow::log::Ostream_log_msg_writer::m_cached_rounded_time_stamp</a></div><div class="ttdeci">std::chrono::time_point&lt; std::chrono::system_clock, std::chrono::seconds &gt; m_cached_rounded_time_stamp</div><div class="ttdoc">As used in the caching-for-perf algorithm in do_log_with_human_friendly_time_stamp(),...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00237">ostream_log_msg_writer.hpp:237</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a7ac568ffa478c6fc64775c23b00d3fb3"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a7ac568ffa478c6fc64775c23b00d3fb3">flow::log::Ostream_log_msg_writer::log_past_time_stamp</a></div><div class="ttdeci">void log_past_time_stamp(const Msg_metadata &amp;metadata, util::String_view msg)</div><div class="ttdoc">Remainder of log() functionality after either do_log_with_epoch_time_stamp() or do_log_with_human_fri...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8cpp_source.html#l00165">ostream_log_msg_writer.cpp:165</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_a9a95b0f429db5e9b19055cf251b063a7"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#a9a95b0f429db5e9b19055cf251b063a7">flow::log::Ostream_log_msg_writer::m_config</a></div><div class="ttdeci">const Config &amp; m_config</div><div class="ttdoc">Reference to the config object passed to constructor. See notes on thread safety.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00212">ostream_log_msg_writer.hpp:212</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_aa05b822916ceb37db219ec73563b146d"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aa05b822916ceb37db219ec73563b146d">flow::log::Ostream_log_msg_writer::~Ostream_log_msg_writer</a></div><div class="ttdeci">~Ostream_log_msg_writer() noexcept</div><div class="ttdoc">Restores formatting state of os to how it was before entry to constructor.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8cpp_source.html#l00070">ostream_log_msg_writer.cpp:70</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_aaf6caa588e382495f7605da38caa42bf"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aaf6caa588e382495f7605da38caa42bf">flow::log::Ostream_log_msg_writer::m_clean_os_state</a></div><div class="ttdeci">Ostream_state m_clean_os_state</div><div class="ttdoc">Formatter state of m_os at construction. Used at least in destructor (as of this writing) to restore ...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00221">ostream_log_msg_writer.hpp:221</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_ab0f5d7c5f289defcded5fa3560059411"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#ab0f5d7c5f289defcded5fa3560059411">flow::log::Ostream_log_msg_writer::do_log_with_epoch_time_stamp</a></div><div class="ttdeci">void do_log_with_epoch_time_stamp(const Msg_metadata &amp;metadata, util::String_view msg)</div><div class="ttdoc">log() implementation with time stamp = seconds.microseconds since Epoch.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8cpp_source.html#l00079">ostream_log_msg_writer.cpp:79</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_aba0a94e36e435aeb67bbc25fee8380f7"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#aba0a94e36e435aeb67bbc25fee8380f7">flow::log::Ostream_log_msg_writer::log</a></div><div class="ttdeci">void log(const Msg_metadata &amp;metadata, util::String_view msg)</div><div class="ttdoc">Logs to the wrapped ostream the given message and associated metadata like severity and time stamp; p...</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8cpp_source.html#l00074">ostream_log_msg_writer.cpp:74</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Ostream__log__msg__writer_html_ac37b6d6bbfb5c9feefd35fd78cc66dad"><div class="ttname"><a href="classflow_1_1log_1_1Ostream__log__msg__writer.html#ac37b6d6bbfb5c9feefd35fd78cc66dad">flow::log::Ostream_log_msg_writer::m_os</a></div><div class="ttdeci">std::ostream &amp; m_os</div><div class="ttdoc">Reference to stream to which to log messages.</div><div class="ttdef"><b>Definition:</b> <a href="ostream__log__msg__writer_8hpp_source.html#l00218">ostream_log_msg_writer.hpp:218</a></div></div>
<div class="ttc" id="aconfig_8hpp_html"><div class="ttname"><a href="config_8hpp.html">config.hpp</a></div></div>
<div class="ttc" id="alog__fwd_8hpp_html"><div class="ttname"><a href="log__fwd_8hpp.html">log_fwd.hpp</a></div></div>
<div class="ttc" id="anamespaceflow_1_1log_html"><div class="ttname"><a href="namespaceflow_1_1log.html">flow::log</a></div><div class="ttdoc">Flow module providing logging functionality.</div><div class="ttdef"><b>Definition:</b> <a href="async__file__logger_8cpp_source.html#l00027">async_file_logger.cpp:28</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_ae4dc52186797094b3040379ff19124c9"><div class="ttname"><a href="namespaceflow_1_1util.html#ae4dc52186797094b3040379ff19124c9">flow::util::String_view</a></div><div class="ttdeci">Basic_string_view&lt; char &gt; String_view</div><div class="ttdoc">Commonly used char-based Basic_string_view. See its doc header.</div><div class="ttdef"><b>Definition:</b> <a href="string__view_8hpp_source.html#l00191">string_view.hpp:191</a></div></div>
<div class="ttc" id="astructflow_1_1log_1_1Msg__metadata_html"><div class="ttname"><a href="structflow_1_1log_1_1Msg__metadata.html">flow::log::Msg_metadata</a></div><div class="ttdoc">Simple data store containing all of the information generated at every logging call site by flow::log...</div><div class="ttdef"><b>Definition:</b> <a href="log_8hpp_source.html#l01040">log.hpp:1041</a></div></div>
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